New research of interest has been published in the journal eLife (“A live attenuated-vaccine model confers cross-protective immunity against different species of the Leptospira genus”). This is based on a study that discusses how a single-dose universal vaccine could protect against the many forms of leptospirosis bacteria, which cause life-threatening conditions such as Weil’s disease and lung haemorrhage.
Leptospira bacteria refers to genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species. The bacteria are flexulous, in terms of being able to bend and wriggle as well as motile, in terms of being able to propel themselves about. It is of medical concern that the disease caused by the bacterium is manifest as a wide range of symptoms, some of which may be mistaken for other diseases. The time between exposure to the bacteria which causes leptospirosis and when symptoms first become apparent is 7 to 21 days.
To create the vaccine, microbiologists pinpointed a novel protein called FcpA, positioned on the flagella of Leptospira. This appendage allows which enables the bacterium to move and penetrate the tissues of animals. This led to experiments being conducted with genetically engineered Leptospira, where the bacteria were developed so they lacked a functional FcpA molecule.
The development of the new vaccine has been demonstrated using a mouse model. With the studies, all traces of the inoculated pathogen into the animals cleared within seven days (with hamsters) and after two weeks (in mice).
Post-testing assessment of the animals indicated they generated antibodies that were able to recognise a broad range of proteins across different infectious bacteria.
The researchers conclude that through further review of the antibody response other proteins can used as targets for future vaccines. Remarkably, the majority of these proteins (70 percent) appear similar across the 13 disease-causing species of Leptospira. This infers that the proteins are necessary for bacterial survival and hence they could provide effective future vaccine candidates.
